OpenAPI & ExpressJS - Only the first property printed in response

I'm reading from 2 json files, each of which contain an array of students/teachers.

let student = require('../data/student.json');
let teacher = require('../data/teacher.json');

When I call:

res.status(200).json({student: student}, {teacher: teacher});

Only the first(student, in this case) gets printed in the response. Teacher isn't printed.

In my yaml file, I have this for the format of the response message.

content:
   application/json:
      schema:
         $ref: '#/components/schemas/StudentsAndTeachers'

This is StudentsAndTeachers:

StudentsAndTeachers:
      type: object
      properties:
        student: 
          type: array
          items:
            $ref: '#/components/schemas/Person'
        teacher: 
          type: array
          items:
            $ref: '#/components/schemas/Person'
      required:
        - student
        - teacher

This is Person:

Person:
      type: object
      properties:
        id:
          type: string
        name:
          type: string
      required:
        - id
        - name

Why is only the first property (student) being printed in the response?

this is the error I'm getting:

500 
Error: Internal Server Error

Response body
{
  "message": ".response should have required property 'teacher',
  "errors": [
    {
      "path": ".response.teacher",
      "message": "should have required property 'teacher'",
      "errorCode": "required.openapi.validation"
    },
  ],
  "status": 500
}